diff options
author | Stefano Garzarella <sgarzare@redhat.com> | 2019-11-14 10:57:46 +0100 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2019-11-15 03:12:18 +0100 |
commit | c0cfa2d8a788fcf45df5bf4070ab2474c88d543a (patch) | |
tree | dc3b586aec205e319eaf827cdf6022fc17610c41 /net/vmw_vsock/af_vsock.c | |
parent | hv_sock: set VMADDR_CID_HOST in the hvs_remote_addr_init() (diff) | |
download | linux-c0cfa2d8a788fcf45df5bf4070ab2474c88d543a.tar.xz linux-c0cfa2d8a788fcf45df5bf4070ab2474c88d543a.zip |
vsock: add multi-transports support
This patch adds the support of multiple transports in the
VSOCK core.
With the multi-transports support, we can use vsock with nested VMs
(using also different hypervisors) loading both guest->host and
host->guest transports at the same time.
Major changes:
- vsock core module can be loaded regardless of the transports
- vsock_core_init() and vsock_core_exit() are renamed to
vsock_core_register() and vsock_core_unregister()
- vsock_core_register() has a feature parameter (H2G, G2H, DGRAM)
to identify which directions the transport can handle and if it's
support DGRAM (only vmci)
- each stream socket is assigned to a transport when the remote CID
is set (during the connect() or when we receive a connection request
on a listener socket).
The remote CID is used to decide which transport to use:
- remote CID <= VMADDR_CID_HOST will use guest->host transport;
- remote CID == local_cid (guest->host transport) will use guest->host
transport for loopback (host->guest transports don't support loopback);
- remote CID > VMADDR_CID_HOST will use host->guest transport;
- listener sockets are not bound to any transports since no transport
operations are done on it. In this way we can create a listener
socket, also if the transports are not loaded or with VMADDR_CID_ANY
to listen on all transports.
- DGRAM sockets are handled as before, since only the vmci_transport
provides this feature.
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/vmw_vsock/af_vsock.c')
-rw-r--r-- | net/vmw_vsock/af_vsock.c | 243 |
1 files changed, 184 insertions, 59 deletions
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index 8985d9d417f0..5357714b6104 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -130,7 +130,12 @@ static struct proto vsock_proto = { #define VSOCK_DEFAULT_BUFFER_MAX_SIZE (1024 * 256) #define VSOCK_DEFAULT_BUFFER_MIN_SIZE 128 -static const struct vsock_transport *transport_single; +/* Transport used for host->guest communication */ +static const struct vsock_transport *transport_h2g; +/* Transport used for guest->host communication */ +static const struct vsock_transport *transport_g2h; +/* Transport used for DGRAM communication */ +static const struct vsock_transport *transport_dgram; static DEFINE_MUTEX(vsock_register_mutex); /**** UTILS ****/ @@ -182,7 +187,7 @@ static int vsock_auto_bind(struct vsock_sock *vsk) return __vsock_bind(sk, &local_addr); } -static int __init vsock_init_tables(void) +static void vsock_init_tables(void) { int i; @@ -191,7 +196,6 @@ static int __init vsock_init_tables(void) for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) INIT_LIST_HEAD(&vsock_connected_table[i]); - return 0; } static void __vsock_insert_bound(struct list_head *list, @@ -376,6 +380,68 @@ void vsock_enqueue_accept(struct sock *listener, struct sock *connected) } EXPORT_SYMBOL_GPL(vsock_enqueue_accept); +/* Assign a transport to a socket and call the .init transport callback. + * + * Note: for stream socket this must be called when vsk->remote_addr is set + * (e.g. during the connect() or when a connection request on a listener + * socket is received). + * The vsk->remote_addr is used to decide which transport to use: + * - remote CID <= VMADDR_CID_HOST will use guest->host transport; + * - remote CID == local_cid (guest->host transport) will use guest->host + * transport for loopback (host->guest transports don't support loopback); + * - remote CID > VMADDR_CID_HOST will use host->guest transport; + */ +int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk) +{ + const struct vsock_transport *new_transport; + struct sock *sk = sk_vsock(vsk); + unsigned int remote_cid = vsk->remote_addr.svm_cid; + + switch (sk->sk_type) { + case SOCK_DGRAM: + new_transport = transport_dgram; + break; + case SOCK_STREAM: + if (remote_cid <= VMADDR_CID_HOST || + (transport_g2h && + remote_cid == transport_g2h->get_local_cid())) + new_transport = transport_g2h; + else + new_transport = transport_h2g; + break; + default: + return -ESOCKTNOSUPPORT; + } + + if (vsk->transport) { + if (vsk->transport == new_transport) + return 0; + + vsk->transport->release(vsk); + vsk->transport->destruct(vsk); + } + + if (!new_transport) + return -ENODEV; + + vsk->transport = new_transport; + + return vsk->transport->init(vsk, psk); +} +EXPORT_SYMBOL_GPL(vsock_assign_transport); + +bool vsock_find_cid(unsigned int cid) +{ + if (transport_g2h && cid == transport_g2h->get_local_cid()) + return true; + + if (transport_h2g && cid == VMADDR_CID_HOST) + return true; + + return false; +} +EXPORT_SYMBOL_GPL(vsock_find_cid); + static struct sock *vsock_dequeue_accept(struct sock *listener) { struct vsock_sock *vlistener; @@ -414,6 +480,9 @@ static int vsock_send_shutdown(struct sock *sk, int mode) { struct vsock_sock *vsk = vsock_sk(sk); + if (!vsk->transport) + return -ENODEV; + return vsk->transport->shutdown(vsk, mode); } @@ -530,7 +599,6 @@ static int __vsock_bind_dgram(struct vsock_sock *vsk, static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr) { struct vsock_sock *vsk = vsock_sk(sk); - u32 cid; int retval; /* First ensure this socket isn't already bound. */ @@ -540,10 +608,9 @@ static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr) /* Now bind to the provided address or select appropriate values if * none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY). Note that * like AF_INET prevents binding to a non-local IP address (in most - * cases), we only allow binding to the local CID. + * cases), we only allow binding to a local CID. */ - cid = vsk->transport->get_local_cid(); - if (addr->svm_cid != cid && addr->svm_cid != VMADDR_CID_ANY) + if (addr->svm_cid != VMADDR_CID_ANY && !vsock_find_cid(addr->svm_cid)) return -EADDRNOTAVAIL; switch (sk->sk_socket->type) { @@ -592,7 +659,6 @@ static struct sock *__vsock_create(struct net *net, sk->sk_type = type; vsk = vsock_sk(sk); - vsk->transport = transport_single; vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY); vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY); @@ -629,11 +695,6 @@ static struct sock *__vsock_create(struct net *net, vsk->buffer_max_size = VSOCK_DEFAULT_BUFFER_MAX_SIZE; } - if (vsk->transport->init(vsk, psk) < 0) { - sk_free(sk); - return NULL; - } - return sk; } @@ -649,7 +710,10 @@ static void __vsock_release(struct sock *sk, int level) /* The release call is supposed to use lock_sock_nested() * rather than lock_sock(), if a sock lock should be acquired. */ - vsk->transport->release(vsk); + if (vsk->transport) + vsk->transport->release(vsk); + else if (sk->sk_type == SOCK_STREAM) + vsock_remove_sock(vsk); /* When "level" is SINGLE_DEPTH_NESTING, use the nested * version to avoid the warning "possible recursive locking @@ -677,7 +741,8 @@ static void vsock_sk_destruct(struct sock *sk) { struct vsock_sock *vsk = vsock_sk(sk); - vsk->transport->destruct(vsk); + if (vsk->transport) + vsk->transport->destruct(vsk); /* When clearing these addresses, there's no need to set the family and * possibly register the address family with the kernel. @@ -894,7 +959,7 @@ static __poll_t vsock_poll(struct file *file, struct socket *sock, mask |= EPOLLIN | EPOLLRDNORM; /* If there is something in the queue then we can read. */ - if (transport->stream_is_active(vsk) && + if (transport && transport->stream_is_active(vsk) && !(sk->sk_shutdown & RCV_SHUTDOWN)) { bool data_ready_now = false; int ret = transport->notify_poll_in( @@ -1144,7 +1209,6 @@ static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr, err = 0; sk = sock->sk; vsk = vsock_sk(sk); - transport = vsk->transport; lock_sock(sk); @@ -1172,19 +1236,26 @@ static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr, goto out; } + /* Set the remote address that we are connecting to. */ + memcpy(&vsk->remote_addr, remote_addr, + sizeof(vsk->remote_addr)); + + err = vsock_assign_transport(vsk, NULL); + if (err) + goto out; + + transport = vsk->transport; + /* The hypervisor and well-known contexts do not have socket * endpoints. */ - if (!transport->stream_allow(remote_addr->svm_cid, + if (!transport || + !transport->stream_allow(remote_addr->svm_cid, remote_addr->svm_port)) { err = -ENETUNREACH; goto out; } - /* Set the remote address that we are connecting to. */ - memcpy(&vsk->remote_addr, remote_addr, - sizeof(vsk->remote_addr)); - err = vsock_auto_bind(vsk); if (err) goto out; @@ -1584,7 +1655,7 @@ static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg, goto out; } - if (sk->sk_state != TCP_ESTABLISHED || + if (!transport || sk->sk_state != TCP_ESTABLISHED || !vsock_addr_bound(&vsk->local_addr)) { err = -ENOTCONN; goto out; @@ -1710,7 +1781,7 @@ vsock_stream_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, lock_sock(sk); - if (sk->sk_state != TCP_ESTABLISHED) { + if (!transport || sk->sk_state != TCP_ESTABLISHED) { /* Recvmsg is supposed to return 0 if a peer performs an * orderly shutdown. Differentiate between that case and when a * peer has not connected or a local shutdown occured with the @@ -1884,7 +1955,9 @@ static const struct proto_ops vsock_stream_ops = { static int vsock_create(struct net *net, struct socket *sock, int protocol, int kern) { + struct vsock_sock *vsk; struct sock *sk; + int ret; if (!sock) return -EINVAL; @@ -1909,7 +1982,17 @@ static int vsock_create(struct net *net, struct socket *sock, if (!sk) return -ENOMEM; - vsock_insert_unbound(vsock_sk(sk)); + vsk = vsock_sk(sk); + + if (sock->type == SOCK_DGRAM) { + ret = vsock_assign_transport(vsk, NULL); + if (ret < 0) { + sock_put(sk); + return ret; + } + } + + vsock_insert_unbound(vsk); return 0; } @@ -1924,11 +2007,20 @@ static long vsock_dev_do_ioctl(struct file *filp, unsigned int cmd, void __user *ptr) { u32 __user *p = ptr; + u32 cid = VMADDR_CID_ANY; int retval = 0; switch (cmd) { case IOCTL_VM_SOCKETS_GET_LOCAL_CID: - if (put_user(transport_single->get_local_cid(), p) != 0) + /* To be compatible with the VMCI behavior, we prioritize the + * guest CID instead of well-know host CID (VMADDR_CID_HOST). + */ + if (transport_g2h) + cid = transport_g2h->get_local_cid(); + else if (transport_h2g) + cid = transport_h2g->get_local_cid(); + + if (put_user(cid, p) != 0) retval = -EFAULT; break; @@ -1968,24 +2060,13 @@ static struct miscdevice vsock_device = { .fops = &vsock_device_ops, }; -int __vsock_core_init(const struct vsock_transport *t, struct module *owner) +static int __init vsock_init(void) { - int err = mutex_lock_interruptible(&vsock_register_mutex); + int err = 0; - if (err) - return err; - - if (transport_single) { - err = -EBUSY; - goto err_busy; - } - - /* Transport must be the owner of the protocol so that it can't - * unload while there are open sockets. - */ - vsock_proto.owner = owner; - transport_single = t; + vsock_init_tables(); + vsock_proto.owner = THIS_MODULE; vsock_device.minor = MISC_DYNAMIC_MINOR; err = misc_register(&vsock_device); if (err) { @@ -2006,7 +2087,6 @@ int __vsock_core_init(const struct vsock_transport *t, struct module *owner) goto err_unregister_proto; } - mutex_unlock(&vsock_register_mutex); return 0; err_unregister_proto: @@ -2014,28 +2094,15 @@ err_unregister_proto: err_deregister_misc: misc_deregister(&vsock_device); err_reset_transport: - transport_single = NULL; -err_busy: - mutex_unlock(&vsock_register_mutex); return err; } -EXPORT_SYMBOL_GPL(__vsock_core_init); -void vsock_core_exit(void) +static void __exit vsock_exit(void) { - mutex_lock(&vsock_register_mutex); - misc_deregister(&vsock_device); sock_unregister(AF_VSOCK); proto_unregister(&vsock_proto); - - /* We do not want the assignment below re-ordered. */ - mb(); - transport_single = NULL; - - mutex_unlock(&vsock_register_mutex); } -EXPORT_SYMBOL_GPL(vsock_core_exit); const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk) { @@ -2043,12 +2110,70 @@ const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk) } EXPORT_SYMBOL_GPL(vsock_core_get_transport); -static void __exit vsock_exit(void) +int vsock_core_register(const struct vsock_transport *t, int features) +{ + const struct vsock_transport *t_h2g, *t_g2h, *t_dgram; + int err = mutex_lock_interruptible(&vsock_register_mutex); + + if (err) + return err; + + t_h2g = transport_h2g; + t_g2h = transport_g2h; + t_dgram = transport_dgram; + + if (features & VSOCK_TRANSPORT_F_H2G) { + if (t_h2g) { + err = -EBUSY; + goto err_busy; + } + t_h2g = t; + } + + if (features & VSOCK_TRANSPORT_F_G2H) { + if (t_g2h) { + err = -EBUSY; + goto err_busy; + } + t_g2h = t; + } + + if (features & VSOCK_TRANSPORT_F_DGRAM) { + if (t_dgram) { + err = -EBUSY; + goto err_busy; + } + t_dgram = t; + } + + transport_h2g = t_h2g; + transport_g2h = t_g2h; + transport_dgram = t_dgram; + +err_busy: + mutex_unlock(&vsock_register_mutex); + return err; +} +EXPORT_SYMBOL_GPL(vsock_core_register); + +void vsock_core_unregister(const struct vsock_transport *t) { - /* Do nothing. This function makes this module removable. */ + mutex_lock(&vsock_register_mutex); + + if (transport_h2g == t) + transport_h2g = NULL; + + if (transport_g2h == t) + transport_g2h = NULL; + + if (transport_dgram == t) + transport_dgram = NULL; + + mutex_unlock(&vsock_register_mutex); } +EXPORT_SYMBOL_GPL(vsock_core_unregister); -module_init(vsock_init_tables); +module_init(vsock_init); module_exit(vsock_exit); MODULE_AUTHOR("VMware, Inc."); |